"Keto-friendly" labels: 9 marketing tricks on packaged food
"Keto-friendly" and "net carbs" are not FDA-defined. Here are 9 packaged-food label tricks, from maltitol math to tiny servings, and how to read past them.
- 'Keto-friendly' and 'net carbs' are not defined by the FDA. The brand decides what they mean.
- The most common trick is subtracting all sugar alcohols, including maltitol, which raises blood sugar.
- Tiny serving sizes and the 'under 0.5 g counts as zero' rule make carbs look smaller than they are.
- Some 'fibers' in bars behave like carbs. A small study found IMO raised blood glucose and insulin.
- Ignore the front of the pack. Read total carbohydrate, fiber, the ingredient list and the serving size.
A "keto-friendly" label means whatever the brand wants it to mean. The FDA has not defined "keto," "keto-friendly" or "net carbs," and it does not allow "low carb" as a nutrient claim at all, according to a food-law summary of the rules. So the badge on the front of a bar, a bag of cookies or a pint of ice cream is marketing, not a standard. The only numbers on the package that follow federal rules are on the Nutrition Facts panel and the ingredient list, and even those have gaps. Here are the nine tricks to watch for.
Why keto labels are a free-for-all
US nutrition labeling is governed by 21 CFR 101.9, which sets out how total carbohydrate, fiber, sugars and sugar alcohols are declared. Front-of-pack claims like "sugar free" are separately defined in 21 CFR 101.60.
Carbohydrate claims fall into a hole between those rules. The law-firm summary from Olsson Frank Weeda notes that total carbohydrate "may not be characterized as 'low'," that "net carbs" has no regulatory definition, and that keto certifications "do not provide a regulatory defense." FDA sent warning letters over "low-carb" phrasing during the early-2000s Atkins boom. Today's industry mostly sidesteps that with words that sound like a claim without being one.
Trick 1: the giant "net carbs" number
The front says "3 g NET CARBS" in huge type. The Nutrition Facts panel, which is regulated, says 22 g total carbohydrate. The difference is whatever the brand decided to subtract: fiber, sugar alcohols, allulose, sometimes all three.
That subtraction is not illegal, but it is not standardized either. One brand's "net" is not comparable to another's. Always restart from total carbohydrate on the panel and do your own subtraction.
Trick 2: subtracting maltitol like it is fiber
The most common way to shrink a net-carb number is to subtract every gram of sugar alcohol. That is roughly fair for erythritol, which has a glycemic index of about 0. It is not fair for maltitol, which has a glycemic index of about 35 (sucrose is 65), per a review of polyols in Nutrition Research Reviews. Maltitol syrup (polyglycitol) is about 39.
A bar with 20 g total carbs, 3 g fiber and 12 g of maltitol might advertise 5 g net. A more honest count, treating maltitol as about half a carb, lands closer to 11 g. Our full breakdown is in sugar alcohols on keto.
Watch out: If the ingredient list says maltitol, maltitol syrup, polyglycitol, hydrogenated starch hydrolysate or just "sugar alcohols" without naming them, do not accept the front-of-pack net carbs. Recalculate, counting those at least at half.
Trick 3: "fiber" that acts like a carb
Fiber is subtracted from net carbs because, in theory, you do not digest it. Some ingredients counted as fiber on labels have been questioned. In a small 2018 study, nine healthy adults took 25 g of isomaltooligosaccharides (IMO), 25 g of soluble corn fiber, or a placebo. IMO raised blood glucose and insulin at 30 minutes compared with both; soluble corn fiber did not. The authors concluded that IMO "does not constitute a dietary fibre."
Since the 2016 label update, FDA's definition limits added "isolated or synthetic" fibers to those it has determined have a beneficial physiological effect, which has tightened things up. But fiber names on ingredient lists are still worth reading: if a bar's sweetness and chew come mainly from a syrup-style "fiber," be skeptical of a net-carb number that subtracts it all.
Trick 4: the shrinking serving size
Look at the serving size before anything else. A "2 g net carbs" cookie where a serving is half a cookie is a 4 g cookie. A "1 g net carb" sauce where a serving is one teaspoon is a 3 g sauce if you use a tablespoon.
FDA's 2016 serving-size rule updated reference amounts so labels better reflect what people actually eat, and packages that people commonly finish in one sitting now generally have to be labeled as a single serving or carry a second "per package" column. That helps with snack-size bags. It does not stop a larger bag of keto cookies from using a two-cookie serving, or a pint of keto ice cream from leading with a per-serving number that is a third of the pint.
Trick 5: zero that isn't zero
Under 21 CFR 101.9, a serving with less than 0.5 g of total carbohydrate may be listed as 0 g, and one with less than 1 g may say "less than 1 gram." Calories under 5 per serving may be listed as zero.
This is how a sweetener packet with about 0.9 g of carbs (USDA data for a Splenda packet) and a "zero-calorie" cooking spray both show zero. Combine the rounding with a tiny serving size and a product can be built to round down on purpose. Three servings of a "0 g" product can be 1.5 g; ten can be several grams.
Trick 6: "sugar free" and "no added sugar"
These are real, regulated claims, but they are about sugar, not carbs.
- "Sugar free" means less than 0.5 g of sugars per serving (21 CFR 101.60). Starch, flour, maltodextrin and sugar alcohols do not count as "sugars" for this rule.
- "No added sugar" means no sugar or sugar-containing ingredient (like jam or concentrated fruit juice) was added during processing. The food can still be high in naturally occurring sugar or starch.
USDA data shows how far apart "sugar free" and "low carb" can be: sugar-free peanut butter cookies are about 13.7 g net carbs per three cookies, with 0 g of sugar listed.
Trick 7: the word "keto" itself
"Keto," "keto-friendly," "keto-certified," "carb-smart," "carb-conscious" and "lifestyle-friendly" all suggest a product is low in carbohydrate without making a claim FDA would treat as one. A certification seal means a private organization approved it under its own criteria, which you usually cannot see on the pack.
Some keto-branded products genuinely are very low carb. The point is that the word does not tell you which ones. A "keto granola" built on cashews, coconut and a sweetener blend can still carry a meaningful share of your daily carbs per bowl.
Trick 8: the health-halo sugars
"Sweetened with dates," "coconut sugar," "raw honey," "monk fruit blend," "maple." These sound clean. Most of them are just sugar.
| Food | Net carbs per serving | Verdict |
|---|---|---|
| Medjool date | about 16.4 g per date | Not keto |
| Honey | about 17.3 g per tbsp | Not keto |
| Maple syrup | about 13.4 g per tbsp | Not keto |
| Granulated sugar | about 4.2 g per tsp | Not keto |
| Granola bar, plain | about 14.8 g per 25 g bar | Not keto |
| Sugar-free peanut butter cookies | about 13.7 g per 3 cookies | Not keto |
| Sugar-free hard candy (sorbitol) | about 3 g per piece | Careful |
| Pork rinds, plain | 0 g per 1 oz | Keto |
Figures from USDA FoodData Central SR Legacy (total carbohydrate minus fiber). Brands vary.
Watch "monk fruit blends" and "stevia blends" too. The sweet extract itself has negligible carbs, but blends are often bulked out with erythritol (fine), dextrose or maltodextrin (not fine) or even regular sugar.
Trick 9: the tolerance gap
FDA's compliance rules for labels say a product is misbranded if calories, sugars, fat or sodium come in more than 20 percent above the labeled value (21 CFR 101.9(g)(5)). Total carbohydrate is listed separately among nutrients where "reasonable excesses" are acceptable under good manufacturing practice. In plain English, the rule that polices understated sugar does not police understated total carbohydrate in the same way.
Most manufacturers label in good faith, and calories still put a ceiling on how far off carbs can be. But if a "2 g net carb" product reliably seems to stall you, you are not imagining that labels have some slack.
Bunny tip: Run a 30-second label check: (1) serving size, (2) total carbohydrate, (3) fiber, (4) every sweetener and "fiber" in the ingredient list. Subtract fiber and erythritol or allulose, count maltitol at least half, and multiply by how many servings you will really eat.
How to read a keto label in 30 seconds
- Skip the front. Badges, seals and giant net-carb numbers are marketing.
- Check the serving size and how many servings are in the package.
- Start from total carbohydrate, not net carbs.
- Subtract dietary fiber, unless the main "fiber" is something you are skeptical of.
- Identify the sweeteners. Erythritol and allulose can be subtracted. FDA lets allulose be left out of total and added sugars, but it still sits inside total carbohydrate on the label, so you subtract it yourself. Maltitol and unnamed sugar alcohols get counted.
- Multiply by the servings you will actually eat.
- Compare the result to your daily limit. If one snack is a third of your day, it is not a snack.
If you have diabetes, especially if you use insulin, packaged "keto" products can affect your glucose differently from what the label suggests. Check with your doctor or a dietitian, and test your own response when you can.
For the bigger picture, our lists of hidden carbs and hidden sugar in sauces and condiments cover the foods that cause problems even without a "keto" badge.
Track it with KetoBunny: Snap a photo of what you ate and KetoBunny logs the carbs and macros for the amount you actually ate, then updates your ketosis estimate, so a three-serving pint gets counted as three servings.
The bottom line
Packaged keto food can be useful, but the label is written to sell it. "Keto-friendly" is not a standard, "net carbs" is the brand's own math, and "0 g" means "less than half a gram per our chosen serving." Read the Nutrition Facts panel and the ingredient list, do your own subtraction, and be especially wary of maltitol, mystery fibers and tiny serving sizes.
Snap a meal and Bunny counts the net carbs and the hidden fat, then keeps an honest estimate of your ketosis.
Frequently asked
What does keto-friendly mean on a label?
Nothing official. 'Keto' and 'keto-friendly' are not FDA-defined terms, and third-party keto certifications are private programs, not regulatory standards. Treat the phrase as marketing and check the numbers yourself.
Are net carbs on labels accurate?
Net carbs are not a regulated number. Brands usually subtract fiber and sugar alcohols, sometimes allulose, and the method varies. Recalculate from total carbohydrate using the ingredient list.
Can a product labeled 0 g carbs have carbs?
Yes. FDA rules let a serving with less than 0.5 g of total carbohydrate be labeled 0 g. Several servings of a 'zero' product can add up to real carbs.
Why can't brands say 'low carb'?
FDA has never defined 'low' for carbohydrate, so 'low carb' is not an authorized nutrient content claim. Brands use softer phrases like 'keto-friendly' or 'carb-conscious' instead.
Are keto protein bars actually keto?
Some are. Many rely on maltitol, IMO-type 'fibers' or small serving sizes to hit a low net-carb number. Check the sweetener and fiber sources in the ingredient list before trusting the front.
Sources
- Low-Carb Food Labeling: What FDA Rules Mean for Food Manufacturers — Olsson Frank Weeda (food law firm)
- 21 CFR 101.9 Nutrition labeling of food — Cornell Law School Legal Information Institute
- 21 CFR 101.60 Nutrient content claims for the calorie content of foods — eCFR
- Food Labeling: Serving Sizes of Foods That Can Reasonably Be Consumed at One Eating Occasion — Federal Register (FDA final rule, 2016)
- The effects of soluble corn fibre and isomaltooligosaccharides on blood glucose, insulin, digestion and fermentation (Lowery et al., 2018) — Journal of Metabolic Health
- Health potential of polyols as sugar replacers (Livesey, 2003) — Nutrition Research Reviews
- FDA allows low-calorie sweetener allulose to be excluded from total and added sugars counts — US Food and Drug Administration
This article is general information, not medical advice. Talk to your doctor before starting keto if you take medication for diabetes or blood pressure, are pregnant or breastfeeding, or have kidney disease.